Skylights and roof windows have been incorporated into buildings for decades as a way of introducing daylight and/or fresh air into a building interior. A skylight, which may be fixed or opening, typically is installed within a rooftop that is inaccessible from the building's interior without the use of a ladder. Most skylights include an insulated glass lens or covering element, a wood frame, and protective cladding, and some may be mounted directly to the roof deck (those being referred to as “deck-mounted” skylights). Flashing (sometimes referred to as “step-flashing”) or other protective materials may also be used to create a watertight barrier around the skylight opening.
A roof window is designed for installation in homes or buildings where the roof is generally within reach of the building occupant. For example, roof windows may be installed in homes having low roof lines or in attics being used as living space. The roof window may possess a similar construction to a skylight, and may include opening, or ventilating, capability.
Such deck-mounted skylights and roof windows (collectively referred to herein as “skylights”) are installed around a pre-cut opening within a roof. As with any window, steps must be taken to ensure that rain, wind, and the like are prevented from entering the home through the skylight opening. Particularly in colder climates that are prone to snow, where thawing and refreezing are common, a potential exists for melted snow or other precipitation to seep into the building around the perimeter of the skylight. To minimize the likelihood of leakage, skylight manufacturers typically recommend that a felt paper or a barrier paper (such as Grace's Ice and Water Shield® barrier paper, manufactured by W.R. Grace and Company of Connecticut) be applied around the curb or wood frame of the skylight assembly. Such paper or barrier material may be used in addition to the metal step-flashing commonly used around the perimeter of the skylight.
Unfortunately, it has been found that the protective underlayment may be applied incorrectly or may be omitted entirely, thus increasing the likelihood of a problem with the skylight installation. Step-flashings provide some protection against water, air, and moisture leaks, but their effectiveness is dependent, at least in part, upon the skill of the installer.
Accordingly, it would be desirable for a skylight to be provided with an effective air and moisture barrier that is readily attachable to the skylight assembly and to the roof and whose presence minimizes the likelihood of problematic leaking of the skylight.